Cable-tightening device

ABSTRACT

A cable-tightening device of the kind in which the cable is wedged between two parts which are clamped against each other when a tractive pull is applied in one direction on the cable, while the latter is free to slide through the device when the direction of the pull is reversed, comprising a tubular casing having a wall traversed by an oblique channel located in a radial plane and intended for the passage of the cable, and a cylindrical rotatable plug with longitudinal nipples mounted inside the tubular casing and elastically urged towards the cable-channel outlet, the longitudinal chamber formed inside the casing having a quadrilateral section and the diameter of the plug being slightly less than the dimension of the quadrilateral section in said radial plane.

United States Patent 1191 Moransais 1 1 Jan. 9, 1973 [54]CABLE-TIGHTENING DEVICE FOREIGN PATENTS OR APPLICATIONS 1 1 lnvantorlCharles Moransais, La Boisse, 345,304 12/1936 Italy ..24/136.2

France [73] Assignee: Zaiira France, La Boisse, France PrimaryExaminer-Robert Rlordon Assistant Examiner-Roscoe V. Parker, Jr. [22]Flled: June 1970 Att0rney-Charles E. Baxley, Frank M. Nolan and 21 Appl.No.2 41,805 Thomas Tate [30] Foreign Application Priority Data [57]ABSTRACT June 2, 1969 France ..6917990 A caple'nghtenmg devlce of the fwh'ch the Oct. '281 969 France .J 4113933931 cable wedged between twoparts much are clamped against each other when a tractive pull isapplied in one direction on the cable, while the latter is free to liil1138!.1131;111:131:ijjjjijiijiijjjiifffiisfi133$ hhhe hhhhhhh hhe hehhewheh hhe hhehhhh of he h [58] Field 0 Search81/3 J; 24/126 B 136 A 244 Ris reversed, comprising a tubular casing having a wall 24/171,194traversed by an oblique channel located in a radial plane and intendedfor the passage of the cable, and a 5 References Cited cylindricalrotatable plug with longitudinal nipples mounted inside the tubularcasing and elastically UNITED STATES PATENTS urged towards thecable-channel outlet, the longitu- 2,346,477 4/1944 Ederer ..24/136.2 xdinal chamber formed inside the casing having 3 3,517,420 6/1970 Anzimi..24/126L quadrilateral Section and the diameter of the P 3,189,0386/1965 Von Pechmann ..24/126.2 X being slightly less than the dimensionof the quadri- 637,239 11/1899 Davis ..24/126.2 lateral section in saidradial plane. 225,923 3/1880 Fenton... ..24/I36.2 2,632,932 3/1953 Blake..24/l36.2 5 Claims, 7 Drawing Figures PATENTEDJAH 91973 3,709,071

SHEET 1 [IF 2 PATENTEDJAH 9197s I 3.709.071

sum 2 [1F 2 CABLE-TIGHTENING DEVICE The present invention relates to acable-tightening device, .in which the cable is wedged between two partswhich are clamped against each other when a tractive pull is applied inone direction on the cable, the latter on the contrary being free toslide in the tightening device when it is pulled in the oppositedirection.

One type of tightening device is known which is constituted by a framehaving the form of a tube with circular sections in which is formed,from the interior to the exterior, an oblique channel for the passage ofthe cable. A moving member or plug, substantially spherical, is actedupon by a spring in the direction for which it grips the cable engagedin the channel, so that the gripping action is practically ensured assoon as the plug is applied against the cable.

In tightening devices of this type, it is necessary to provide thespherical plug with two fins extending outside the tube and capable ofmoving in two longitudinal windows formed in the tube, in order topermit the user to move the spherical plug back so as to allow theengagement of the cable in its channel, or its release as the case maybe.

However, these lateral fins increase the cost price of the unit:

both by their existence, that of the fixing means (keys) and by themachining which is necessary on the parts;

and also by the time required for the assembly of the unit.

Now, the assembly operations for this type of article, which must beextremely cheap, have a predominating influence on the cost price; thus,in the present case, the assembly of fins on the spherical plugrepresents a considerable increase in the prices of these tighteningdevices.

Cable tighteners are furthermore known which have a cylindrical plughoused in a U-section frame, the extremities of the plug sliding inwindows formed in the frame and projecting to the exterior, therebypermitting manual operation of the plug. However, for considerations ofstrength, the structure of this plug necessitates the use of a metalframe, since the clamping forces are applied exclusively at the level ofthe walls in which the windows are pierced.

In addition, when the plug is actuated by a spring, this latter, to beeffective, must be fixed to the frame since at least one wall of theframe is open.

The fact that the frame must be made of metal and that the spring, wherethis is used, necessitates a special assembly, results in highmanufacturing costs.

Thus, the two known types of tightening devices have the disadvantagesof complexity of assembly and high cost.

The present invention has for its object to overcome these disadvantagesand in particular to produce a tightening device of simple constructionand low production cost.

A cable-tightening device according to the invention comprises a tubularframe having a wall traversed by an oblique channel located in a radialplane and intended for the passage of the cable, and a plug movableinside the tubular frame and elastically urged by a spring towards theextremity at which the channel opens towards the interior of the frame,and this tightening device is characterized in that the longitudinalchamber provided in the tubular frame has a section of quadrilateralshape, and the plug is constituted by a substantially cylindrical body,the diameter of which is slightly less than the dimension of thequadrilateral section located in the said radial plane.

The said plug body is extended laterally and on each side by two nipplescapable of moving in appropriate longitudinal windows in the tubularframe. The diameter of these nipples is less than the height of thewindows, so that when the cable is clamped by the plug, the latter issupported along one of its generator lines against the wall of the frameopposite to that in which is formed the oblique passage channel for thecable. The clamping force is thus distributed over the two oppositewalls of the tubular chamber.

The good distribution of this clamping force makes it possible toconstruct the frame of moulded thermoplastic material, which enables thecost of manufacture to be still further reduced.

The plug is made in a single piece, either of metal such aschromium-plated steel or of plastic material. In addition, the sectionof the plug body may be either cylindrical or slightly ovoid, theprincipal axis of the section being then preferably directed along thelongitudinal axis of the chamber.

By virtue of the arrangement according to the invention, the assemblyand dismantling of the plug inside the frame are easy.

According to an especially advantageous form of the invention, thelateral nipples are large enough to prevent the plug from escaping outof the tubular frame and are short enough to permit engagement of theplug obliquely in the tubular frame without it being necessary toprovide other handling means than the projecting extremities of the twosmall nipples.

In certain cases of application however, it may be necessary to employ aplug with long nipples, and in this case its engagement in the framecannot be carried out as indicated above.

The said plug is then introduced laterally into the frame through acircular opening formed behind at least one of the longitudinal windows.

Finally, in the case where the extremities of the nipples, intended tobe located after placing the plug in position outside the frame, have awidth greater than the width of the windows, each of the longitudinalwindows will terminate at the rear in a circular opening having adiameter greater than the extremities of the nipples, in order to permitthe plug to be introduced laterally.

According to a further object of the invention, the frame comprises, asin the case of known tightening devices, hooking means permitting thetightener to be hooked either to one extremity of the cable itself, orat a fixed attachment point, the said frame and the hooking means beingmade in a single piece of moulded thermo-plastic material, which resultsin an appreciable economy during the course of manufacture.

More particularly, the hooking means is constituted by an extension ofthe frame, which is pierced with a simple hole.

This form of construction enables the economy obtained by a one-piececonstruction to be combined with adequate strength of the hooking meansto withstand the traction forces of the cable.

Other advantages and characteristic features of the invention will bebrought out during the course of the description which follows below ofa few forms of construction, given by way of example, reference beingmade to the accompanying drawings, in which:

FIG. 1 is a preferred form of construction of a tightening deviceaccording to the invention, having a one-piece frame;

FIG. 2 is a longitudinal section taken along the line 11-11 ofFIG. 1;

FIG. 3 is a horizontal longitudinal section showing the placing inposition of the cylindrical plug with short nipples, of the tighteningdevice of FIG. 1;

FIG. 4 is a longitudinal section similar to FIG. 3 showing thetightening device ready for use;

FIG. 5 is a transverse section taken along the line V-V of FIG. 2;

FIGS. 6 and 7 show an alternative form of the plug mounted in atightening device according to the invention.

In the drawings, there has been generally indicated at l the frame of atightening device according to the invention, made of mouldedthermo-plastic material and integrally moulded with an end extension 2in which is formed a hole 3, this extension permitting the attachment ofthe tightening device on an anchorage element of any kind.

In the preferred form of embodiment shown, the frame has an externalsection of quadrilateral shape, that is to say rectangular orsubstantially square, as shown in the drawing, and it is pierced at itsfront portion with an axial chamber 4, also having a quadrilateralsection. In the example shown, this section is rectangular but it willbe understood that it could be square.

The quadrilateral external shape of the frame permits this latter to becoupled to the extension 2 by two opposite converging slopes 2a, which,while retaining the strength of the frame, permits an economy ofmaterial. It will be noted that, in order that the traction forcesapplied on the frame act under the best possible conditions, that is tosay in the axis of the frame, the extension 2 will preferably extend asshown in the vertical plane of the frame with respect to FIG. 1, or inthe horizontal plane.

The chamber 4 is extended in the interior of the frame by a blind hole 5of circular section, in which is housed a spring 6 intended toco-operate with a cylindrical plug 7 mounted in the chamber 4. Thecylindrical plug is provided with two lateral cylindrical nipples 8 and9 which are housed in lateral windows 10 and 11 formed in the oppositelyfacing walls of the frame. These windows extend from the bottom of therectangular-section chamber 4 up to a zone relatively towards the front.

An oblique channel 12 formed in the lower face of the frame 1 enablesacable 13 to be engaged under the plug 7. The spring 6 applies the plug 7against the cable 13 and any tension force applied on the cable in thedirection of the arrow F will have the effect of increasing the clampingof the cable underneath the plug. On the other hand, if the cable issubjected to a force in the direction opposite to the arrow F, the plugwill slightly compress the spring 6 and the cable will be allowed toslide under the plug.

For rapid mounting and removal of the plug 7 in the frame, there hasbeen provided a circular opening 14 at the rear extremity of the window10, the diameter of this opening being slightly greater than that of theplug 7 plug enable the latter to be obliquely directed between thewindows 10 and 11, as has been shown in broken lines on FIG. 3.

If the precaution is taken of introducing the spring 6 and holding itback by means of a piece P engaged in the windows, the introduction ofthe cylindrical plug 7 (position in broken lines) can be effected veryeasily, and it is only necessary to release the spring by removing thepiece P for the assembly to be in the operating condition, following theconventional principle of wedging, that is to say the plug 7 applyingthe cable 13 against the wall of the tubular frame.

In this way, the small nipples 8 and 9 have sufficient length to providesuitable engagement, illustrated in FIG. 4, without it being necessaryto mount fittings on each side of the plug 7 so as to give asatisfactory grip for the fingers. In consequence, the unit can beassembled very quickly, the plug 7 being immediately acted upon, as soonas the assembly is complete, by the spring 6 towards the end abutments10a of the windows 10 and 1 1. t

The removal of the plug is effected simply by moving it back to thebottom of the chamber 5 so that the nipples are located level with theopening 14. The plug is then extracted by sliding it laterally in theopening 14 which is of larger diameter.

As can more particularly be seen from FIG. 5, the internal arrangementof the tightening device is such that when the plug 7 wedges the cableagainst the lower wall 15 of the frame (which may advantageously bereinforced in the zone of the channel), the upper generator line of theplug is applied against the upper wall 16 of the chamber 4. Thus, theclamping effect is mainly applied on the facing upper wall 16 and lowerwall 15 of the frame in the direction of the vertical arrows. If theexternal section of the frame were circular, there would be formed, inthe vicinity of the angles of the chamber 4, zones of lower strengthwhich could eventually result, due to the effect of large forces, incracking or even bursting of the frame. BY giving the frame aquadrilateral (square or rectangular) external section corresponding toits internal section, there is obtained a wall of constant thicknesshaving satisfactory strength.

It is furthermore possible to increase this strength still more bygiving the frame a square external section for a chamber having arectangular section.

The plug of FIGS. 1 to 5 is provided with short nipples which permit itsintroduction as indicated with reference to FIGS. 3 and 4. In certaincases of application however, it may be necessary to have a plug withlong nipples 20, as shown in broken lines in FIG. 5, or alternativelythe plug may be provided as in FIG. 6 with nipples 21, terminated attheir extremity which is to be located outside the frame, by a portionof larger size, such as a hemispherical larger portion 22, for example.

In both these cases, the introduction of the plug into the frame cannotbe carried out in the manner described with reference to FIGS. 3 and 4.

In the case of a plug with long nipples (FIG. 5), it is introducedlaterally through the circular opening 14, after having pushed back thespring 6, and a transverse sliding movement will be sufficient to placeit in position. The removal of the plug is effected in the inverseorder.

On the other hand (see FIGS. 6 and 7) in the case of a plug 21 withenlarged extremities, the frame must necessarily be provided with twocircular openings 14a, 14b behind the longitudinal windows, theseopenings having a sufficient diameter to permit the lateral introductionof the plug, as shown in FIG. 7.

It will be noted that the plug may be made either ofa metal such aschromium-plated steel, or of moulded plastic material.

In addition, although a plug with a cylindrical section has beendescribed, it should be observed that it could have a section of anyother suitable form.

Thus, a plug having an ovoid section with its major axis directedsubstantially along the longitudinal axis of the chamber would enablethe clamping effect of the plug on the cable to be increased.

What I claim is:

I. A cable-tightening device comprising in combination:

a tubular frame with a wall in which passes an oblique channel locatedin a radial plane and intended for passage ofthe cable;

a plug adapted to move in the interior of said tubular frame andelastically urged towards the extremity at which said channel opens intothe interior;

a longitudinal chamber formed in said tubular frame, said chamber havinga section of quadrilateral shape, and said plug constituted by asubstantially cylindrical body having a diameter slightly less than thedimension of said quadrilateral section located in the radial plane ofsaid channel;

said tubular frame pierced with two longitudinal windows diametricallyopposite on each side of said channel, and in which the body of saidplug is extended on each side by a nipple the diameter of which is lessthan the width of the window in which said nipple is intended to beengaged;

said cable-tightening device further provided with a circular openinghaving a diameter slightly greater than that of the body of said plugand located at the rear extremity of at least one of said longitudinalwindows.

2. A cable-tightening device comprising in combination:

a tubular frame with a wall in which passes an oblique channel locatedin a radial plane and intended for passage of the cable;

a plug adapted to move in the interior of said tubular frame andelastically urged towards the extremity at which said channel opens intothe interior;

a longitudinal chamber formed in said tubular frame, said chamber havinga section of quadrilateral shape, and said plug constituted by asubstantially cylindrical body having a diameter slightly less than thedimension of said quadrilateral section located in the radial plane ofsaid channel' said tubular frame pierced with two longitudinal windowsdiametrically opposite on each side of said channel, and in which thebody of said plug is extended on each side by a nipple the diameter ofwhich is less than the width of the window in which said nipple isintended to be engaged;

said nipples being short, the total of said plug complete with itsnipples being substantially less than the length of each of thelongitudinal windows of said frame and greater than the width of theframe measured over the two opposite walls in which said windows areformed, said plug with short nipples being introduced into position orremoved by pivoting obliquely in said chamber and moving laterally alongthe axis of said chamber.

3. A cable-tightening device as claimed in claim I, in which said plugis provided with long nipples, said plug being introduced into the framelaterally through the circular opening formed at the rear extremity ofat least one of said longitudinal windows.

4. A cable-tightening device as claimed in claim 1, in which theextremities of said nipples intended to be located, after placing theplug in position, outside said frame; have a width greater than that ofsaid windows and less than the diameter of the circular openings formedat the rear extremity of at least one of said longitudinal windows, inorder to permit the lateral introduction of said plug.

5. A cable-tightening device comprising in combination:

a tubular frame with a wall in which passes an oblique channel locatedin a radial plane and intended for passage of the cable;

a plug adapted to move in the interior of said tubular frame andelastically urged towards the extremity at which said channel opens intothe interior;

a longitudinal chamber formed in said tubular frame, said chamber havinga section of quadrilateral shape with a constant section through theentire length of the chamber, and said plug constituted by asubstantially cylindrical body having a diameter slightly less than thedimension of said quadrilateral section located in the radial plane ofsaid channel;

said tubular frame pierced with two longitudinal windows diametricallyopposite on each side of said channel and in which the body of said plugis extended on each side by a nipple the diameter of which is less thanthe width of the window in which said nipple is engaged.

1. A cable-tightening device comprising in combination: a tubular framewith a wall in which passes an oblique channel located in a radial planeand intended for passage of the cable; a plug adapted to move in theinterior of said tubular frame and elastically urged towards theextremity at which said channel opens into the interior; a longitudinalchamber formed in said tubular frame, said chamber having a section ofquadrilateral shape, and said plug constituted by a substantiallycylindrical body having a diameter slightly less than the dimension ofsaid quadrilateral section located in the radial plane of said channel;said tubular frame pierced with two longitudinal windows diametricallyopposite on each side of said channel, and in which the body of saidplug is extended on each side by a nipple the diameter of which is lessthan the width of the window in which said nipple is intended to beengaged; said cable-tightening device further provided with a circularopening having a diameter slightly greater than that of the body of saidplug and located at the rear extremity of at least one of saidlongitudinal windows.
 2. A cable-tightening device comprising incombination: a tubular frame with a wall in which passes an obliquechannel located in a radial plane and intended for passage of the cable;a plug adapted to move in the interior of said tubular frame andelastically urged towards the extremity at which said channel opens intothe interior; a longitudinal chamber formed in said tubular frame, saidchamber having a section of quadrilateral shape, and said plugconstituted by a substantially cylindrical body having a diameterslightly less than the dimension of said quadrilateral section locatedin the radial plane of said channel; said tubular frame pierced with twolongitudinal windows diametrically opposite on each side of saidchannel, and in which the body of said plug is extended on each side bya nipple the diameter of which is less than the width of the window inwhich said nipple is intended to be engaged; said nipples being short,the total of said plug complete with its nipples being substantiallyless than the length of each of the longitudinal windows of said frameand greater than the width of the frame measured over the two oppositewalls in which said windows are formed, said plug with short nipplesbeing introduced into position or removed by pivoting obliquely in saidchamber and moving laterally along the axis of said chamber.
 3. Acable-tightening device as claimed in claim 1, in which said plug isprovided with long nipples, said plug being introduced into the framelaterally through the circular opening formed at the rear extremity ofat least one of said longitudinal windows.
 4. A cable-tightening deviceas claimed in claim 1, in which the extremities of said nipples intendedto be located, after placing the plug in position, outside said frame,have a width greater than that of said windows and less than thediameter of the circular openings formed at the rear extremity of atleast one of said longitudinal windows, in order to permit the lateralintroduction of said plug.
 5. A cable-tightening device comprising incombination: a tubular frame with a wall in which passes an obliquechannel located in a radial plane and intended for passage of the cable;a plug adapted to move in the interior of said tubular frame andelastically urged towards the extremity at which said channel opens intothe interior; a longitudinal chamber formed in said tubular frame, saidchamber having a section of quadrilateral shape with a constant sectionthrough the entire length of the chamber, and said plug constituted by asubstantially cylindrical body having a diameter slightly less than thedimension of said quadrilateral section located in the radial plane ofsaid channel; said tubular frame pierced with two longitudinal windowsdiametrically opposite on each side of said channel and in which thebody of said plug is extended on each side by a nipple the diameter ofwhich is less than thE width of the window in which said nipple isengaged.